Ma Zi Ren Wan

Purported Benefits, Side Effects & More

Ma Zi Ren Wan

Purported Benefits, Side Effects & More
Ma Zi Ren Wan

Common Names

  • Hemp Seed Pill
  • Hemp Seed Formula
  • Mashiningan
  • TJ-126

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

Ma Zi Ren Wan (MZRW) is a traditional Chinese medicine (TCM) formula. It’s made up of six different herbs. 

What are the potential uses and benefits?

Ma Zi Ren Wan is used to:

  • Treat constipation (difficult or infrequent bowel movements)

Talk with your healthcare provider before taking herbal formulas. They can interact with some medications and affect how they work. For more information, read the “What else do I need to know?” section below.

What are the side effects?

Side effects of MZRW may include:

  • Abdominal pain
  • Cramping and bloating
  • Nausea (feeling like you’re going to throw up)
  • Vomiting (throwing up)
  • Headache
  • Worsened rhinitis (runny nose and stuffiness)
  • Diarrhea (loose or watery bowel movements)
  • Gas
  • Difficulty urinating
  • Dizziness
What else do I need to know?
  • Talk to your healthcare provider if you have tree nut allergy. Ma Zi Ren Wan contains apricot kernels that can cause an allergic reaction.

For Healthcare Professionals

Clinical Summary

Ma Zi Ren Wan (MZRW) is a traditional Chinese medicine (TCM) formula with a long history of use as a treatment for constipation. Documented in Shang Han Lun (TCM Treatise on Cold-induced Disorders), it consists of six herbs: Huo Ma Ren (Fructus Cannabis), Da Huang (Radix et Rhizoma Rhei), Bai Shao (Radix Paeoniae Alba), Xing Ren (Semen Armeniacae Amarum), Zhi Shi (Fructus Aurantii Immaturus), and Hou Pu (Cortex Magnoliae Officinalis). According to a systematic review, MZRW is the most commonly used herbal formula for constipation in China (1), particularly by elderly patients and women (2) (3). A population-based study reported it is also among the formulas commonly prescribed to prostate cancer patients in Taiwan (4).

Much of available data of MZRW’s clinical effects are limited to Asian populations. In a three-armed randomized controlled trial involving patients with functional constipation, MZRW was found to be equally effective as senna, a popular herbal laxative, in increasing complete spontaneous bowel movement (CSBM). Compared to the senna and placebo groups, the MZRW arm also had a significant increase in colonic transit along with decreased severity in straining, constipation, incomplete evacuation, and global constipation symptoms. Benefits were also more durable in the MZRW group (5). Similar improvements have been reported in other randomized double-blind studies. Patients with functional constipation who took MZRW had increased CSBM and reductions in constipation severity and use of rescue therapy compared to the placebo group (6). In a pilot RCT for palliative cancer patients with constipation, modified MZRW was well-tolerated, increased in stool frequency, and reduced constipation severity and straining versus placebo (16).

A systematic review and meta-analysis (17 trials, 1681 patients) concluded that MZRW is beneficial against functional constipation in Asian populations. In addition, MZRW did not increase adverse events compared to controls (7). Of note, four studies in this review involved pediatric (8) (9) and adult cancer patients with chemotherapy-induced (10) and opioid-associated (11) constipation.

More well-designed trials are needed to strengthen the evidence base surrounding MZRW. Methodologically robust studies are also warranted to determine its potential in relieving non-functional constipation, as well as effectiveness in diverse populations.

Purported Uses and Benefits
  • Constipation
Mechanism of Action

The mechanisms of action via which MZRW exerts its effects are not fully known. Findings to date suggest that its componentsFructus Immaturus Citri Aurantii (Zhi Shi), Semen Cannabis Sativae (Ma Zi Ren, also known as Huo Ma Ren) and Semen Pruni Armeniacae (Xing Ren) – may soften stool, reduce water absorption, activate intestinal mucosa, and reestablish gastrointestinal homeostasis to strengthen colonic motility and alleviate constipation. Treatment with MZRW has also been associated with decreased levels of circulating oleamide, a known regulator of intestinal motility (12) (13).


Patients with tree nut allergy should avoid MZRW as it contains apricot kernels.

Adverse Reactions

Abdominal pain, cramping, bloating, diarrhea, gas, nausea, vomiting, headache, dizziness, urination difficulty, and worsened rhinitis (5) (6) (14) (15) (8).

Herb-Drug Interactions

None known.

Dosage (OneMSK Only)
  1. Zhong LLD, Zheng G, Da Ge L, et al. Chinese herbal medicine for constipation: zheng-based associations among herbs, formulae, proprietary medicines, and herb-drug interactions.Chin Med. 2016 Jun 23;11:28.
  2. Takayama S, Iwasaki K. Systematic review of traditional Chinese medicine for geriatrics. Geriatr Gerontol Int. 2017;17(5):679-688.
  3. Chen LC, Wang BR, Chen IC, Shao CH. Use of Chinese herbal medicine among menopausal women in Taiwan. Int J Gynaecol Obstet. 2010;109(1):63-66.
  4. Lin YH, Chen KK, Chiu JH. Coprescription of Chinese Herbal Medicine and Western Medications among Prostate Cancer Patients: A Population-Based Study in Taiwan. Evid Based Complement Alternat Med. 2012;2012:147015.
  5. Zhong LLD, Cheng CW, Kun W, et al. Efficacy of MaZiRenWan, a Chinese herbal medicine, in patients with functional constipation in a randomized controlled trial. Clin Gastroenterol Hepatol. 2019;17(7):1303-1310.e1318.
  6. Cheng CW, Bian ZX, Zhu LX, Wu JC, Sung JJ. Efficacy of a Chinese herbal proprietary medicine (hemp seed pill) for functional constipation. Am J Gastroenterol. 2011;106(1):120-129.
  7. Yang M, Feng Y, Zhang YL, et al. Herbal formula MaZiRenWan (hemp seed pill) for constipation: A systematic review with meta-analysis. Phytomedicine. 2021;82:153459.
  8. Zhang GJ, Zheng YD, Shen XL, Fang YY. Clinical observation of 30 cases of children with gastrointestinal dry and hot constipation treated with hemp seed pill. Chinese Pediatrics of Integrated Traditional and Western Medicine. 2014;6:459–461.
  9. Chang YS. A clinical Study on the treatment of functional chronic constipation in children with hemp seed pill. Chinese Pediatrics of Integrated Traditional and Western Medicine. 2017;9:216–218.
  10. Lu XY.Treatment of 45 cases of constipation caused by chemotherapy with hemp seed pill. Henan Traditional Chinese Medicine. 2014;34:810-811.
  11. Li XY, Li HJ, Yang M. Therapeutic effect of modified MaZiRen pill for treating constipation caused by opium alike. Chinese Journal of Experimental Traditional Medical Formula. 2012;18:312-314.
  12. Huang T, Ning Z, Hu D, et al. Uncovering the mechanisms of Chinese herbal medicine (MaZiRenWan) for functional constipation by focused network pharmacology approach. Front Pharmacol. 2018;9:270.
  13. Huang T, Zhao L, Lin CY, et al. Chinese herbal medicine (MaZiRenWan) improves bowel movement in functional constipation through down-regulating oleamide. Front Pharmacol. 2019;10:1570.
  14. Pan HP, Duan YS. Observation on 48 cases of drug-induced constipation treated with hemp seed pill. Journal of Practical Traditional Chinese Medicine. 2010;26:150-151.
  15. Zhang Q, Gao P. Clinical observation on the treatment of constipation after chemotherapy with hemp seed pill. Journal of Liaoning University of Traditional Chinese Medicine. 2009;11:117-118.
  16. Cheng CW, Mok HF, Yau CWS, et al. A pilot randomized placebo-controlled study on modified MaZiRenWan: a formulated Chinese medicine to relieve constipation for palliative cancer patients. Chin Med. Mar 2 2022;17(1):31.
Email your questions and comments to [email protected].

Last Updated